Direct Measurement of the Critical Velocity Above Which a Tuning Fork Generates Turbulence in Superfluid Helium
Direct Measurement of the Critical Velocity Above Which a Tuning Fork Generates Turbulence in Superfluid Helium
复制标题
直接测量超流氦中音叉产生湍流的临界速度
DOI：
10.1007/s10909-009-0026-5
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发表时间：
2009
影响因子：
2
通讯作者：
Efimov V
中科院分区：
文献类型：
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作者：
Efimov V
在饱和蒸气压力下，在1.3<；T<；4.2kK温度范围内，在液氦-4中实验研究了电驱动8 GHz石英音叉的动力学。与最近调查中使用的标准32 GHz叉子相比，该叉子的尺寸相对较大。用间接机电等效法测量叉叉尖端的速度，并与通过迈克尔逊干涉法直接光学测量振荡幅度所测得的另一种8赫兹叉子的速度进行比较。这些结果的比较提供了向湍动状态转变的临界速度的绝对值。
The dynamics of an electrically-driven 8 kHz quartz tuning fork has been studied experimentally in liquid helium-4 in the temperature range 1.3<T<4.2 K under the saturated vapour pressure. The fork has relatively large dimensions compared to standard 32 kHz fork used in recent investigations. The velocity of the tip of the fork prong is measured by the indirect electromechanical equivalent method and is compared with the velocity of another 8 kHz fork (from the same batch) determined by direct optical measurement of the oscillation amplitude through Michelson interferometry. A comparison of these results has provided absolute values for the critical velocity of the transition to the turbulent state.